Re: [PATCH 1/3] docs: Add support for TPM devices over I2C bus

[Ninad Palsule]

On 3/24/23 3:01 AM, Cédric Le Goater wrote:
> On 3/24/23 06:11, Ninad Palsule wrote:
> > Hello Cedric,
> >
> > Joel helped me to configure the device and we are able to configure 
> > tpm device on ast2600-evb.
> >
> > I will include this example in the documentation.
> >
> > # uname -a
> > Linux ast2600-evb 6.1.15 #1 SMP Thu Mar 23 20:48:29 CDT 2023 armv7l 
> > GNU/Linux
> > # cat /etc/os-release
> > NAME=Buildroot
> > VERSION=2023.02-dirty
> > ID=buildroot
> > VERSION_ID=2023.02
> > PRETTY_NAME="Buildroot 2023.02"
> >
> > # echo tpm_tis_i2c 0x2e > /sys/bus/i2c/devices/i2c-12/new_device
> > [   59.681684] tpm_tis_i2c 12-002e: 2.0 TPM (device-id 0x1, rev-id 1)
> > [   59.703190] tpm tpm0: A TPM error (256) occurred attempting the 
> > self test
> > [   59.705215] tpm tpm0: starting up the TPM manually
> > [   59.892917] i2c i2c-12: new_device: Instantiated device 
> > tpm_tis_i2c at 0x2e
> > # cd /sys/class/tpm/tpm0
> > # ls
> > dev                pcr-sha256         power              uevent
> > device             pcr-sha384         subsystem
> > pcr-sha1           pcr-sha512         tpm_version_major
>
>
> Nice. Did you need any special support in the kernel ?
>
> I could update this image for avocado tests :
>
> https://github.com/legoater/qemu-aspeed-boot/tree/master/images/ast2600-evb/buildroot-2023.02

Kernel need a TPM i2c driver support. I built it with following head on 
dev-6.1 branch. You also need to run "echo" command I mentioned above to 
instantiate the device. Also start the swtpm as provided in my earlier mail.

$ git rev-parse HEAD
0e94476a8892056a9242bcd75e59e7d2b92ac435

Thanks,

Ninad


> Thanks,
>
> C.